Artificial Watershed Gets First Rain

The world’s only artificial watershed inside the Biosphere 2 at the University of Arizona receives its first rain, giving researchers the first opportunity to study how water, soil, plants, and microbes interact in a realistic setting; this rare chance could help improve future global climate models.

Dec 04, 2012

A recent rain in Tucson, AZ., allowed spouting from a network of pipes transport thousands of gallons of water down into the artificial watershed inside the Biosphere 2 at the University of Arizona. Inside the biosphere, there are three manmade hilltops that were constructed to form the Landscape Evolution Observatory (LEO). Each hill contains more than 1,800 sensors and samplers that sense and track the flow of water through soil and drawing samples for analysis. The recent rain has allowed researchers to study all the interactions of water, soil, plants, and microbes in a very realistic environment and situation.

"It's the first time anyone has built an instrument like that," said Biosphere 2 Science Director Peter Troch, a professor in the UA's department of hydrology and water resources. "LEO provides the scientific community with a tool to learn about the landscape in ways we haven't been able to before. It will help us to really understand Earth's surface processes."

LEO, which is housed inside the biosphere’s greenhouse dome, provides researchers with real evidence of how the changing climate will impact water movement and how the atmosphere interacts with soil. The biosphere will also allow the scientists to adjust various environmental conditions and study those different outcomes, which is something that could not be done in the natural world.

"We can change the climate to drier or more extreme conditions and see how well the predictions based on our computer models hold up," Troch said. "For example, we may predict that the Sonoran Desert ecosystem may turn into shrub or grassland, but those are just predictions. LEO can help validate those predictions."

The observations made with LEO will not be limited to the arid Southwest. Results from this 10-year project will allow researchers to improve global climate models, while the simulations will also make predictions more realistic and reliable. The project scientists expect LEO to create collaborations among researchers from across the world, bringing together diverse disciplines.